Subject and Purpose. The InN Gunn diode is known as the device capable of generating powerful oscillations atfrequencies above 300 GHz. A possible way for increasing both the microwave power and the cutoff frequency of the Gunn diode is to employ graded-gap semiconductors. The subject of this research is the process for generating electrical oscillations in InN and graded-gap GaInN Gunn diodes that involve resistive contacts at the cathode and the anode, and possess a 1-μm long active region. The research is aimed at suggesting an optimized structure for the graded-gap GaInN diode to obtain a maximum microwave power and maximum frequency of the oscillations, while consuming the lowest possible amount of DC power. Methods and Methodology. А hydrodynamic simulation has been performed of transport of electrons in graded-gap semiconductors, and an integro-differential equation analyzed concerning voltage drop across elements of the related RLC circuit. Results.The power spectra of oscillations have been analyzed for a variety of parameters of both the Gunn diode and the RLC circuit. The frequency dependences of the oscillatory power, characteristic of different electron concentrations, provide evidence for the possibility of obtaining considerable microwave powers at frequencies above 300 GHz through the use of graded-gap GaInN diodes. Conclusion. The results that have been obtained clearly confirm the expected practicality of using a graded GaInN layer in the InN diode for increasing the power of microwave oscillations, reducing the necessary level of the DC power, and restraining the dependence of the output characteristics on the electron density. The highest power of oscillations has been demonstrated by the InN diode with a 0.1 µm long graded-gap layer of GaInN. Meanwhile, the oscillation frequency generated in that diode is somewhat lower than in the InN diode. A compromise between the values of generated power and the oscillation frequency has been reached in the diode with a graded-gap GaInN layer of 0.9 µm in length. In addition, the latter structure requires the lowest level of DC power for effectuating microwave generation at the higher feasible frequencies.
{"title":"TERAHERTZ OSCILLATIONS IN InN GUNN DIODES WITH AN ACTIVE REGION LENGTH OF 1 μm AND WITH A GRADED GaInN LAYER","authors":"I. Storozhenko, S. Sanin","doi":"10.15407/rpra27.04.289","DOIUrl":"https://doi.org/10.15407/rpra27.04.289","url":null,"abstract":"Subject and Purpose. The InN Gunn diode is known as the device capable of generating powerful oscillations atfrequencies above 300 GHz. A possible way for increasing both the microwave power and the cutoff frequency of the Gunn diode is to employ graded-gap semiconductors. The subject of this research is the process for generating electrical oscillations in InN and graded-gap GaInN Gunn diodes that involve resistive contacts at the cathode and the anode, and possess a 1-μm long active region. The research is aimed at suggesting an optimized structure for the graded-gap GaInN diode to obtain a maximum microwave power and maximum frequency of the oscillations, while consuming the lowest possible amount of DC power. Methods and Methodology. А hydrodynamic simulation has been performed of transport of electrons in graded-gap semiconductors, and an integro-differential equation analyzed concerning voltage drop across elements of the related RLC circuit. Results.The power spectra of oscillations have been analyzed for a variety of parameters of both the Gunn diode and the RLC circuit. The frequency dependences of the oscillatory power, characteristic of different electron concentrations, provide evidence for the possibility of obtaining considerable microwave powers at frequencies above 300 GHz through the use of graded-gap GaInN diodes. Conclusion. The results that have been obtained clearly confirm the expected practicality of using a graded GaInN layer in the InN diode for increasing the power of microwave oscillations, reducing the necessary level of the DC power, and restraining the dependence of the output characteristics on the electron density. The highest power of oscillations has been demonstrated by the InN diode with a 0.1 µm long graded-gap layer of GaInN. Meanwhile, the oscillation frequency generated in that diode is somewhat lower than in the InN diode. A compromise between the values of generated power and the oscillation frequency has been reached in the diode with a graded-gap GaInN layer of 0.9 µm in length. In addition, the latter structure requires the lowest level of DC power for effectuating microwave generation at the higher feasible frequencies.","PeriodicalId":33380,"journal":{"name":"Radio Physics and Radio Astronomy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67141913","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Korolev, Y. Karelin, O. Antyufeyev, V. Shulga, V. Myshenko, D. Chechotkin, D. Shulga, O. Patoka, K. Marynko
Subject and Purpose. The work has been aimed at developing and implementing a novel method of aeronomic observations in the Earth's stratosphere, applicable in the microwave range of the electromagnetic spectrum. The research is centered on a study of the measurement errors arising when the method proposed is employed for observations of the ozone spectral line (142 GHz). Methods and Methodology. The method is based on a simplified calibration procedure, in what concerns the hardware and the technology employed. In contrast to the common calibration techniques using special-purpose sources of the reference signal, we suggest resorting to natural sources, like internal noise of the receiver and the thermal radiation from the Earth's surface and the lower atmospheric layer. The measurement errors (both calculated and evaluated experimentally) have been analyzed within standard mathematical statistics techniques. Results. The tests performed during observations of the spectral line (142 GHz) of atmospheric ozone allow considering the new method as a success. The estimated magnitude of the relative error specific to the observation method proposed does not exceed 1.5%. The experimental estimate accounting for all potential error sources does not exceed 5% (with a 1 hour accumulation period), which result corresponds to the current state of the art. Conclusions. The possibility of an essential simplification of the radio optical part of the spectrometer has been demonstrated. The novel calibration technique, as well as the technical implementation thereof, can be recommended as a basis for prospective spectrometers at microwave frequencies.
{"title":"AERONOMIC RADIO SPECTROMETRY WITH CALIBRATION BY SIGNALS FROM VIRTUAL SOURCES","authors":"A. Korolev, Y. Karelin, O. Antyufeyev, V. Shulga, V. Myshenko, D. Chechotkin, D. Shulga, O. Patoka, K. Marynko","doi":"10.15407/rpra27.03.219","DOIUrl":"https://doi.org/10.15407/rpra27.03.219","url":null,"abstract":"Subject and Purpose. The work has been aimed at developing and implementing a novel method of aeronomic observations in the Earth's stratosphere, applicable in the microwave range of the electromagnetic spectrum. The research is centered on a study of the measurement errors arising when the method proposed is employed for observations of the ozone spectral line (142 GHz). Methods and Methodology. The method is based on a simplified calibration procedure, in what concerns the hardware and the technology employed. In contrast to the common calibration techniques using special-purpose sources of the reference signal, we suggest resorting to natural sources, like internal noise of the receiver and the thermal radiation from the Earth's surface and the lower atmospheric layer. The measurement errors (both calculated and evaluated experimentally) have been analyzed within standard mathematical statistics techniques. Results. The tests performed during observations of the spectral line (142 GHz) of atmospheric ozone allow considering the new method as a success. The estimated magnitude of the relative error specific to the observation method proposed does not exceed 1.5%. The experimental estimate accounting for all potential error sources does not exceed 5% (with a 1 hour accumulation period), which result corresponds to the current state of the art. Conclusions. The possibility of an essential simplification of the radio optical part of the spectrometer has been demonstrated. The novel calibration technique, as well as the technical implementation thereof, can be recommended as a basis for prospective spectrometers at microwave frequencies.","PeriodicalId":33380,"journal":{"name":"Radio Physics and Radio Astronomy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67141395","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
G. Ermak, O. Vasilev, A. Varavin, M. Balaban, O. Fateev, V. Zheltov
Subject and Purpose. Proceeding from a mathematical model of the electronically tunable autodyne oscillator (Part І of this paper), essential features of the signal formation / signal processing procedure are considered, as implementable in an autodyne radar that may reveal nonlinearity in its modulation characteristic. The work is aimed at suggesting a digital technique to enable introduction of corrections to the frequency modulation law of the sounding signal and effectuate processing of the data from the close-range autodyne radar (improving its spatial resolution and accuracy of target range measurements). Methods and Methodology. The present analysis of the radiated signal formation and processing of the data from the autodyne radar has been carried out as numerical modeling of spectral, frequency and amplitude characteristics of the radar signals expected, as well as spectral processing of the experimental data from the frequency modulated autodyne radar. Results. An effective law of temporal variations has been suggested for the corrective control voltage of the Gunn diode-based Ka-band autodyne transceiver with a linear law of frequency modulation. The correspondent experimental studies were conducted with an autodyne close-range radar system of Ka-band employing an asymmetric linear frequency modulation with a 500 MHz band of frequency tuning. The use of digital methods for correcting the frequency modulation law has permitted improving the accuracy of target ranging and range resolution up to 0.3 ÷ 0.6 m, which figures correspond to the theoretical limit for the close-range homodyne radar with a 500 MHz tuning band. Conclusion. By linearizing the modulation characteristic of the oscillator and applying digital processing to the autodyne signal in the close-range radar system with a linear frequency modulation law it proves possible to reach ultimately high estimates for the accuracy and resolution of target range measurements. The results obtained can be helpful for developing radar sensors and radiofrequency meters with enhanced parameters and characteristics.
{"title":"SIGNAL FORMATION AND PROCESSING FEATURES FROM AUTODYNE RADAR WITH A WIDE FREQUENCY MODULATION BAND Рart ІІ. Increasing the Resolution of Autodyne Radar by Quasi-Static Correction of the Probe Pulse","authors":"G. Ermak, O. Vasilev, A. Varavin, M. Balaban, O. Fateev, V. Zheltov","doi":"10.15407/rpra27.02.121","DOIUrl":"https://doi.org/10.15407/rpra27.02.121","url":null,"abstract":"Subject and Purpose. Proceeding from a mathematical model of the electronically tunable autodyne oscillator (Part І of this paper), essential features of the signal formation / signal processing procedure are considered, as implementable in an autodyne radar that may reveal nonlinearity in its modulation characteristic. The work is aimed at suggesting a digital technique to enable introduction of corrections to the frequency modulation law of the sounding signal and effectuate processing of the data from the close-range autodyne radar (improving its spatial resolution and accuracy of target range measurements). Methods and Methodology. The present analysis of the radiated signal formation and processing of the data from the autodyne radar has been carried out as numerical modeling of spectral, frequency and amplitude characteristics of the radar signals expected, as well as spectral processing of the experimental data from the frequency modulated autodyne radar. Results. An effective law of temporal variations has been suggested for the corrective control voltage of the Gunn diode-based Ka-band autodyne transceiver with a linear law of frequency modulation. The correspondent experimental studies were conducted with an autodyne close-range radar system of Ka-band employing an asymmetric linear frequency modulation with a 500 MHz band of frequency tuning. The use of digital methods for correcting the frequency modulation law has permitted improving the accuracy of target ranging and range resolution up to 0.3 ÷ 0.6 m, which figures correspond to the theoretical limit for the close-range homodyne radar with a 500 MHz tuning band. Conclusion. By linearizing the modulation characteristic of the oscillator and applying digital processing to the autodyne signal in the close-range radar system with a linear frequency modulation law it proves possible to reach ultimately high estimates for the accuracy and resolution of target range measurements. The results obtained can be helpful for developing radar sensors and radiofrequency meters with enhanced parameters and characteristics.","PeriodicalId":33380,"journal":{"name":"Radio Physics and Radio Astronomy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67141487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Degtyarеv, M. Dubinin, O. Gurin, V. Maslov, K. Muntean, V. Ryabykh, V. Senyuta, O. Svystunov
Subject and Purpose. The problems under consideration concern selection and focusing of higher-order modes in a waveguide-based dielectric laser. The purpose is to clarify the physics underlying the behavior of, and permitting control over, continuous terahertz-frequency laser beams of various spatial polarizations. Methods and Methodology. The mode parameters of the waveguide-based laser resonator involving an inhomogeneous phase-stepped mirror were calculated in a matrix technique. To analyze the propagation and focusing of the laser beams that can be excited in a variety of diffraction zones by the wave modes of a waveguide-based quasi-optical resonator, a vectorial Rayleigh–Sommerfeld theory was used. The pertinent experimental studies were performed with the use of known measurement methods suitable for the terahertz frequency range. Results. A method for selecting the higher-order EH12q-mode of a terahertz-range laser resonator has been suggested, substantiated theoretically and approbated in experiment. It envisages placing an additional element to perform control over the system’s modal structure, namely a (2.3…2.8) λ-wide groove on the surface of one of the resonator mirrors. This measure can significantly increase losses for all undesirable modes. At the same time, the losses for the higher EH12q-mode remain practically unchanged, which creates conditions for its predominant excitation. Theoretical and experimental studies of moderate and ‘sharp’ focusing in free space of higher-order modes with different spatial polarizations of a dielectric waveguide-based resonator have been carried out. Conclusion. As has been shown, the proposed phase-stepped mirror with a groove can effectively select the higher-order transverse modes that may be required. The linearly polarized EH12q-mode has maximum field intensity in the focal region of the lens employed. For azimuthally polarized TE02q- and TE03q-modes the central lobes, noticeably shifted from the focus of the lens, have a field maximum. An increase in the axial intensity is observed upon ‘sharp’ focusing in the field distribution of the radially polarized TM02q- and TM03q-modes. In this case their central lobes, like those of the higher TE0nq-modes, are noticeably shifted from the lens focus.
{"title":"CONTROL OVER HIGHER-ORDER TRANSVERSE MODES IN A WAVEGUIDE-BASED QUASI-OPTICAL RESONATOR","authors":"A. Degtyarеv, M. Dubinin, O. Gurin, V. Maslov, K. Muntean, V. Ryabykh, V. Senyuta, O. Svystunov","doi":"10.15407/rpra27.02.129","DOIUrl":"https://doi.org/10.15407/rpra27.02.129","url":null,"abstract":"Subject and Purpose. The problems under consideration concern selection and focusing of higher-order modes in a waveguide-based dielectric laser. The purpose is to clarify the physics underlying the behavior of, and permitting control over, continuous terahertz-frequency laser beams of various spatial polarizations. Methods and Methodology. The mode parameters of the waveguide-based laser resonator involving an inhomogeneous phase-stepped mirror were calculated in a matrix technique. To analyze the propagation and focusing of the laser beams that can be excited in a variety of diffraction zones by the wave modes of a waveguide-based quasi-optical resonator, a vectorial Rayleigh–Sommerfeld theory was used. The pertinent experimental studies were performed with the use of known measurement methods suitable for the terahertz frequency range. Results. A method for selecting the higher-order EH12q-mode of a terahertz-range laser resonator has been suggested, substantiated theoretically and approbated in experiment. It envisages placing an additional element to perform control over the system’s modal structure, namely a (2.3…2.8) λ-wide groove on the surface of one of the resonator mirrors. This measure can significantly increase losses for all undesirable modes. At the same time, the losses for the higher EH12q-mode remain practically unchanged, which creates conditions for its predominant excitation. Theoretical and experimental studies of moderate and ‘sharp’ focusing in free space of higher-order modes with different spatial polarizations of a dielectric waveguide-based resonator have been carried out. Conclusion. As has been shown, the proposed phase-stepped mirror with a groove can effectively select the higher-order transverse modes that may be required. The linearly polarized EH12q-mode has maximum field intensity in the focal region of the lens employed. For azimuthally polarized TE02q- and TE03q-modes the central lobes, noticeably shifted from the focus of the lens, have a field maximum. An increase in the axial intensity is observed upon ‘sharp’ focusing in the field distribution of the radially polarized TM02q- and TM03q-modes. In this case their central lobes, like those of the higher TE0nq-modes, are noticeably shifted from the lens focus.","PeriodicalId":33380,"journal":{"name":"Radio Physics and Radio Astronomy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67141572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Subject and Purpose. The subject of this research relates to quality parameters of substances with dielectric properties, while the main aim is development of a microwave-band remote sensing technique for measuring quality parameters of solids and loose materials. Methods and Methodology. The work is based on electromagnetic methods for determining substance quality by means of calculations and measurements of microwave signal attenuation in the substance of interest. The methods employed involve electrodynamic analysis of multilayered structures, the analytical method of moments, integral equations of diffraction theory, and objective function optimization. For a certain set of substances, preliminary calibrations and parameter storage are performed, intended for use in the determination of electromagnetic wave attenuation in the substance of interest. By comparing electromagnetic wave attenuation in the substance under testing with correspondent values shown by pre-calibrated samples, with their sets of parameters, it is possible to judge on the quality of the material under consideration. Results. By applying diffraction-theoretic methods of wave analysis in multilayered structures, the electromagnetic field attenuation in a substance (building bricks) has been calculated. The calculatеd results concerning electromagnetic signal attenuation in the test substance were compared with corresponding microwave measurements, thus permitting construction of the structural and mathematical model for the determination of the substance (building bricks) quality. The studies made it possible to evaluate the overall electrodynamic range of the measuring device, choosing the best options for the transmit and receive antenna sensors and the measuring equipment. The method of moments has been used to derive three-dimensional radiation patterns in the proximity of the device and the gain factor of the antenna sensors, wherefrom estimating the mutual electromagnetic effect that the sensors and the test substance may have on each other. Conclusion. Further development of the proposed method may imply refinement of the structural and mathematical models underlying estimation of quality parameters, determination of the overall dynamic range of the microwave-band measuring device, and provisions for automated real-time quality control and monitoring (for instance, on a conveyor), while maintaining conformance to applicable eco-standards concerning microwave intensity levels produced by the device.
{"title":"A POSSIBILITY OF REMOTE QUALITY CONTROL OF MATERIALS: BUILDING BRICKS AS AN EXAMPLE","authors":"V. Ovsyanikov, O. Beznosova","doi":"10.15407/rpra27.02.145","DOIUrl":"https://doi.org/10.15407/rpra27.02.145","url":null,"abstract":"Subject and Purpose. The subject of this research relates to quality parameters of substances with dielectric properties, while the main aim is development of a microwave-band remote sensing technique for measuring quality parameters of solids and loose materials. Methods and Methodology. The work is based on electromagnetic methods for determining substance quality by means of calculations and measurements of microwave signal attenuation in the substance of interest. The methods employed involve electrodynamic analysis of multilayered structures, the analytical method of moments, integral equations of diffraction theory, and objective function optimization. For a certain set of substances, preliminary calibrations and parameter storage are performed, intended for use in the determination of electromagnetic wave attenuation in the substance of interest. By comparing electromagnetic wave attenuation in the substance under testing with correspondent values shown by pre-calibrated samples, with their sets of parameters, it is possible to judge on the quality of the material under consideration. Results. By applying diffraction-theoretic methods of wave analysis in multilayered structures, the electromagnetic field attenuation in a substance (building bricks) has been calculated. The calculatеd results concerning electromagnetic signal attenuation in the test substance were compared with corresponding microwave measurements, thus permitting construction of the structural and mathematical model for the determination of the substance (building bricks) quality. The studies made it possible to evaluate the overall electrodynamic range of the measuring device, choosing the best options for the transmit and receive antenna sensors and the measuring equipment. The method of moments has been used to derive three-dimensional radiation patterns in the proximity of the device and the gain factor of the antenna sensors, wherefrom estimating the mutual electromagnetic effect that the sensors and the test substance may have on each other. Conclusion. Further development of the proposed method may imply refinement of the structural and mathematical models underlying estimation of quality parameters, determination of the overall dynamic range of the microwave-band measuring device, and provisions for automated real-time quality control and monitoring (for instance, on a conveyor), while maintaining conformance to applicable eco-standards concerning microwave intensity levels produced by the device.","PeriodicalId":33380,"journal":{"name":"Radio Physics and Radio Astronomy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67141675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Subject and Purpose. Considerable attention has traditionally been given to the interaction of high-power radio-frequency emissions with the ionosphere. The great many physical effects taking place within the limits of a powerful (heating) facility’s antenna pattern are subjected here to a thorough and detailed analysis. Also, the application of high-power radio emissions provides a convenient means for studying subsystem coupling in the Earth-atmosphere-ionosphere-magnetosphere system, as well as of generation and propagation of disturbances well beyond the antenna pattern of the transmitter. The present paper has been aimed at analyzing the features revealed by the large-scale ionospheric disturbances as these are generated under the impact of either monopulse or periodic radio-frequency emissions from an HF heating facility. Methods and Methodology. In the course of the experiments, the ionosphere was affected with high power radio frequency emission from the heating facility Sura. The disturbances were diagnosed at a distance of 960 km from the heater, with the aid of a vertical incidence Doppler radar. Results. It has been found that through the period of minimal solar activity the ionospheric disturbances observable at a range about 103 km from the heater did arise as the effective radiated power of the latter approached to 25 MW. The duration of the ionospheric response to the impact of an incident monopulse was equal to the length of that latter, while the quasi-periodic variations shown by the Doppler frequency shift just started to appear. The apparent horizontal speed of the propagating disturbances was found to vary from about 300 m/s to 420 m/s. Note that speed to increase at higher altitudes. The periodic mode of heater operation was accompanied by generation of quasi-periodic disturbances in the electron density, of relative amplitudes about 1% and periods close to the Brunt–Väisälä period. Conclusions. The basic features of Doppler spectrum variations, contained in the signals from a diagnostic radar, have been identified in connection with high-power HF radiation incident on the ionosphere
{"title":"FEATURES OF THE LARGE-SCALE IONOSPHERIC DISTURBANCES GENERATED UNDER THE ACTION OF MONOPULSE OR PERIODIC RADIO-FREQUENCY EMISSIONS FROM A HEATING FACILITY","authors":"L. Chernogor, Y. Zhdanko, Y. Luo","doi":"10.15407/rpra27.03.188","DOIUrl":"https://doi.org/10.15407/rpra27.03.188","url":null,"abstract":"Subject and Purpose. Considerable attention has traditionally been given to the interaction of high-power radio-frequency emissions with the ionosphere. The great many physical effects taking place within the limits of a powerful (heating) facility’s antenna pattern are subjected here to a thorough and detailed analysis. Also, the application of high-power radio emissions provides a convenient means for studying subsystem coupling in the Earth-atmosphere-ionosphere-magnetosphere system, as well as of generation and propagation of disturbances well beyond the antenna pattern of the transmitter. The present paper has been aimed at analyzing the features revealed by the large-scale ionospheric disturbances as these are generated under the impact of either monopulse or periodic radio-frequency emissions from an HF heating facility. Methods and Methodology. In the course of the experiments, the ionosphere was affected with high power radio frequency emission from the heating facility Sura. The disturbances were diagnosed at a distance of 960 km from the heater, with the aid of a vertical incidence Doppler radar. Results. It has been found that through the period of minimal solar activity the ionospheric disturbances observable at a range about 103 km from the heater did arise as the effective radiated power of the latter approached to 25 MW. The duration of the ionospheric response to the impact of an incident monopulse was equal to the length of that latter, while the quasi-periodic variations shown by the Doppler frequency shift just started to appear. The apparent horizontal speed of the propagating disturbances was found to vary from about 300 m/s to 420 m/s. Note that speed to increase at higher altitudes. The periodic mode of heater operation was accompanied by generation of quasi-periodic disturbances in the electron density, of relative amplitudes about 1% and periods close to the Brunt–Väisälä period. Conclusions. The basic features of Doppler spectrum variations, contained in the signals from a diagnostic radar, have been identified in connection with high-power HF radiation incident on the ionosphere","PeriodicalId":33380,"journal":{"name":"Radio Physics and Radio Astronomy","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67141825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose: The most important problem of any state is protection of the control and management systems used for the country, national armed forces, high-risk facilities (nuclear power plants, large chemical plants, airports, etc.). Here, the fact that the means of attack can be deployed on ballistic and cruise missiles, aircraft, and drones should be accounted for. The flight altitude of these vehicles varies from ≈300 km to ≈ 10 m. Any attack vehicle is equipped with complex avionics consisting of circuit elements sensitive to electromagnetic fields. Since the 1980s, a new scientific and engineering direction has been developing, being termed as a “functional damage to avionics”. It is based on the creation of powerful means of electromagnetic radiation possessing the energetic capabilities of incapacitating avionics at significant distances (from ~ 100 m to ~ 1000 km). The purpose of this work is to analyze the possible functional damage to avionics with account for the tendencies in avionics technologies. Design/methodology/approach: The analysis is made on the capability of inflicting functional damage to avionics accounting for the modern trends in developing the powerful means of electromagnetic energy generation in the microwave and shorter wavelength ranges, miniaturization and integration of avionics circuit elements. The regression is constructed for the critical energy time dependence. It has been determined that for decades the critical energy required to damage the circuit elements shows a tendency to decrease. This is due to the further miniaturization and integration of microcircuits according to the Moore’s law, which is still valid for now. For a number of circuit elements, the critical energy is found to be in the range of 10-11–10-10 J. At the same time, a reverse tendency arises to protect avionics from being functionally damaged. In this case, the critical energy makes 10-7–10-6 J and greater. From the derived version of the basic equation of functional damage to avionics, the maximum distance at which the damage is possible with the energetics of the existing radio systems is estimated. For the ground-based facilities, this distance can attain hundreds of kilometers. For mobile vehicles, it can reach 10–100 km. Combining target detection, identification and avionics damage capabilities in one radio system has been validated and advised. The transition from the first mode of operation to the second one occurs at shorter distances with an increase of 2–3 orders of magnitude in the pulse energy. Findings: The regression equation has been obtained for the time dependence of the critical energy required for inflicting functional damage to avionics. Its constant decrease has been confirmed. Such a behavior is closely related to the Moore’s law, which characterizes the degree of miniaturization and integration of avionics circuit elements. It has been predicted that for a number of instruments the critical energy can be smaller than
{"title":"FUNCTIONAL DAMAGE OF RADIO ELECTRONIC SYSTEMS","authors":"L. Chernogor","doi":"10.15407/rpra26.04.358","DOIUrl":"https://doi.org/10.15407/rpra26.04.358","url":null,"abstract":"Purpose: The most important problem of any state is protection of the control and management systems used for the country, national armed forces, high-risk facilities (nuclear power plants, large chemical plants, airports, etc.). Here, the fact that the means of attack can be deployed on ballistic and cruise missiles, aircraft, and drones should be accounted for. The flight altitude of these vehicles varies from ≈300 km to ≈ 10 m. Any attack vehicle is equipped with complex avionics consisting of circuit elements sensitive to electromagnetic fields. Since the 1980s, a new scientific and engineering direction has been developing, being termed as a “functional damage to avionics”. It is based on the creation of powerful means of electromagnetic radiation possessing the energetic capabilities of incapacitating avionics at significant distances (from ~ 100 m to ~ 1000 km). The purpose of this work is to analyze the possible functional damage to avionics with account for the tendencies in avionics technologies. Design/methodology/approach: The analysis is made on the capability of inflicting functional damage to avionics accounting for the modern trends in developing the powerful means of electromagnetic energy generation in the microwave and shorter wavelength ranges, miniaturization and integration of avionics circuit elements. The regression is constructed for the critical energy time dependence. It has been determined that for decades the critical energy required to damage the circuit elements shows a tendency to decrease. This is due to the further miniaturization and integration of microcircuits according to the Moore’s law, which is still valid for now. For a number of circuit elements, the critical energy is found to be in the range of 10-11–10-10 J. At the same time, a reverse tendency arises to protect avionics from being functionally damaged. In this case, the critical energy makes 10-7–10-6 J and greater. From the derived version of the basic equation of functional damage to avionics, the maximum distance at which the damage is possible with the energetics of the existing radio systems is estimated. For the ground-based facilities, this distance can attain hundreds of kilometers. For mobile vehicles, it can reach 10–100 km. Combining target detection, identification and avionics damage capabilities in one radio system has been validated and advised. The transition from the first mode of operation to the second one occurs at shorter distances with an increase of 2–3 orders of magnitude in the pulse energy. Findings: The regression equation has been obtained for the time dependence of the critical energy required for inflicting functional damage to avionics. Its constant decrease has been confirmed. Such a behavior is closely related to the Moore’s law, which characterizes the degree of miniaturization and integration of avionics circuit elements. It has been predicted that for a number of instruments the critical energy can be smaller than ","PeriodicalId":33380,"journal":{"name":"Radio Physics and Radio Astronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42883243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Sidorchuk, N. Vasilenko, O. Ulyanov, O. O. Konovalenko, D. Mukha, É. A. Abramenkov, K. M. Sidorchuk, A. I. Miasoied
Purpose: The results of research in continuum decameter-wave radio emission of the Galaxy background, ionized hydrogen regions, supernova remnants, extragalactic discrete sources, extended galaxies, galactic clusters, extragalactic background are given. The aim of this work is reviewing the results achieved for over 50-years of the UTR-2 radiotelescope research of our Galaxy and its population, as well as extragalactic radio sources in the continuum radio emission spectrum at extremely low frequencies for the ground based observations. Design/methodology/approach: The review, analysis, collection of archival data in various publications related to the subjectof this work. Findings: The basic results of studying the ionized hydrogen regions, supernova remnants, Galaxy background emission and its large-scale structure are given, and the maps of these sources are obtained. The catalog of extragalactic discrete radio sources of the most Northern sky part and the cosmological conclusions based on its analysis are described; the estimate of the isotropic extragalactic background brightness temperature is obtained; for the first time, the observational results for the Andromeda galaxy and two galactic clusters Coma and A2255 are given briefly. Conclusions: All the results presented here emphasize the uniqueness and importance of research in the decameter wavelength range, and the large area, flexibility of structure, continuous improvement make the UTR-2 radio telescope an indispensable tool for solving the most important tasks of modern radio astronomy, despite its respectable age. For example, only in the range of 10 to 30 MHz the ionized part of the most common element in the universe, the hydrogen, becomes optically thick and begins to absorb the synchrotron emission on the line of sight, which allows rather easy separation of thermal and non-thermal components of radioemission. This property allows to determine the ionized hydrogen regions’ electron temperature and the electron concentration on the line of sight independently in studying the hydrogen emission regions. When studying the supernova remnants, we can determine the ionized matter location by their spectrum drops ‒ before, inside or behind the remnant. Based on the HB3 supernova remnant radio imagies, an assumption was made on the existence of an ionized hydrogen relic shell aroundit, being caused by the initial ultraviolet flash of a supernova. For the first time, the maps of the Northern sky large-scale structure in the declination range from ‒15° to +85° at extremely low frequencies 10, 12.6, 14.7, 16.7, 20 and 25 MHz for the ground-based observations are published, which, besides their own scientific value, may allow to correct the UTR-2 radio telescope imaging results. Using the full-resolution UTR-2 maps and the developed method of multifrequency T‒T diagrams, it was possible to separate the background radiation into galactic and extragalactic components and construct the spectrum o
{"title":"50 YEARS OF RESEARCH IN CONTINUUM AT THE UTR-2 RADIO TELESCOPE","authors":"M. Sidorchuk, N. Vasilenko, O. Ulyanov, O. O. Konovalenko, D. Mukha, É. A. Abramenkov, K. M. Sidorchuk, A. I. Miasoied","doi":"10.15407/rpra26.04.287","DOIUrl":"https://doi.org/10.15407/rpra26.04.287","url":null,"abstract":"Purpose: The results of research in continuum decameter-wave radio emission of the Galaxy background, ionized hydrogen regions, supernova remnants, extragalactic discrete sources, extended galaxies, galactic clusters, extragalactic background are given. The aim of this work is reviewing the results achieved for over 50-years of the UTR-2 radiotelescope research of our Galaxy and its population, as well as extragalactic radio sources in the continuum radio emission spectrum at extremely low frequencies for the ground based observations. Design/methodology/approach: The review, analysis, collection of archival data in various publications related to the subjectof this work. Findings: The basic results of studying the ionized hydrogen regions, supernova remnants, Galaxy background emission and its large-scale structure are given, and the maps of these sources are obtained. The catalog of extragalactic discrete radio sources of the most Northern sky part and the cosmological conclusions based on its analysis are described; the estimate of the isotropic extragalactic background brightness temperature is obtained; for the first time, the observational results for the Andromeda galaxy and two galactic clusters Coma and A2255 are given briefly. Conclusions: All the results presented here emphasize the uniqueness and importance of research in the decameter wavelength range, and the large area, flexibility of structure, continuous improvement make the UTR-2 radio telescope an indispensable tool for solving the most important tasks of modern radio astronomy, despite its respectable age. For example, only in the range of 10 to 30 MHz the ionized part of the most common element in the universe, the hydrogen, becomes optically thick and begins to absorb the synchrotron emission on the line of sight, which allows rather easy separation of thermal and non-thermal components of radioemission. This property allows to determine the ionized hydrogen regions’ electron temperature and the electron concentration on the line of sight independently in studying the hydrogen emission regions. When studying the supernova remnants, we can determine the ionized matter location by their spectrum drops ‒ before, inside or behind the remnant. Based on the HB3 supernova remnant radio imagies, an assumption was made on the existence of an ionized hydrogen relic shell aroundit, being caused by the initial ultraviolet flash of a supernova. For the first time, the maps of the Northern sky large-scale structure in the declination range from ‒15° to +85° at extremely low frequencies 10, 12.6, 14.7, 16.7, 20 and 25 MHz for the ground-based observations are published, which, besides their own scientific value, may allow to correct the UTR-2 radio telescope imaging results. Using the full-resolution UTR-2 maps and the developed method of multifrequency T‒T diagrams, it was possible to separate the background radiation into galactic and extragalactic components and construct the spectrum o","PeriodicalId":33380,"journal":{"name":"Radio Physics and Radio Astronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45580116","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose: The problem of a plane electromagnetic wave diffraction by an annular slot in the perfectly conducting zero thickness plane is considered. As a dual problem, the problem of diffraction by a perfectly conducting zero thickness ring is also considered. The paper aims at developing the operator method for the axially symmetric structures placed in free space. Design/methodology/approach: The problem is considered in the spectral domain. The scattered field is expressed in terms of unknown Fourier amplitudes (spectral functions). The annular slot is given as a unity of two simple discontinuities, namely of a disk and a circular hole in the plane, which interact with each other. The Fourier amplitude of the scattered field is sought as a sum of two amplitudes, the Fourier amplitude of the field of currents on the disk and Fourier amplitude of the field of currents on the perfectly conducting plane with circular hole. The operator equations are written for these amplitudes, which take into account the electromagnetic coupling of the disk and the hole in the plane. The equations use the reflection operators of a single isolated disk and a single hole in the plane. They are supposed to be known and can be obtained for example by the method of moments.The reflection operators can have singularities. After transformations, the equations are obtained, which are equivalent to the Fredholm integral equations of second kind and they can be solved numerically. Findings: The operator equations relative to the Fourier amplitudes of the field scattered by the discussed structure are obtained. The far zone scattered field for an annular slot and a ring for different values of parameters are studied. Conclusions: The rigorous solution of the problem of the electromagnetic wave diffraction by an annular slot in the plane and by a circular ring is obtained. The problem is reduced to the Fredholm integral equations of second kind. The far field distribution for different parameters is studied. The developed approach is an effective instrument for a number of problems of antenna technique to be solved. Key words: circular hole; disk; annular slot; ring; operator method; diffraction
{"title":"OPERATOR METHOD IN THE PROBLEM OF A PLANE ELECTROMAGNETIC WAVE DIFFRACTION BY AN ANNULAR SLOT IN THE PLANE OR BY A RING","authors":"M. Kaliberda, L. Lytvynenko, S. Pogarsky","doi":"10.15407/rpra26.04.350","DOIUrl":"https://doi.org/10.15407/rpra26.04.350","url":null,"abstract":"Purpose: The problem of a plane electromagnetic wave diffraction by an annular slot in the perfectly conducting zero thickness plane is considered. As a dual problem, the problem of diffraction by a perfectly conducting zero thickness ring is also considered. The paper aims at developing the operator method for the axially symmetric structures placed in free space. Design/methodology/approach: The problem is considered in the spectral domain. The scattered field is expressed in terms of unknown Fourier amplitudes (spectral functions). The annular slot is given as a unity of two simple discontinuities, namely of a disk and a circular hole in the plane, which interact with each other. The Fourier amplitude of the scattered field is sought as a sum of two amplitudes, the Fourier amplitude of the field of currents on the disk and Fourier amplitude of the field of currents on the perfectly conducting plane with circular hole. The operator equations are written for these amplitudes, which take into account the electromagnetic coupling of the disk and the hole in the plane. The equations use the reflection operators of a single isolated disk and a single hole in the plane. They are supposed to be known and can be obtained for example by the method of moments.The reflection operators can have singularities. After transformations, the equations are obtained, which are equivalent to the Fredholm integral equations of second kind and they can be solved numerically. Findings: The operator equations relative to the Fourier amplitudes of the field scattered by the discussed structure are obtained. The far zone scattered field for an annular slot and a ring for different values of parameters are studied. Conclusions: The rigorous solution of the problem of the electromagnetic wave diffraction by an annular slot in the plane and by a circular ring is obtained. The problem is reduced to the Fredholm integral equations of second kind. The far field distribution for different parameters is studied. The developed approach is an effective instrument for a number of problems of antenna technique to be solved. Key words: circular hole; disk; annular slot; ring; operator method; diffraction","PeriodicalId":33380,"journal":{"name":"Radio Physics and Radio Astronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43873351","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Purpose: Investigation of the electrodynamic properties of a Fabry-Perot metaresonator formed by two parallel perfectly conducting, two-dimensionally periodic, two-element screens of finite thickness with rectangular holes. The resonator is excited by a plane linearly polarized electromagnetic wave. The basic cell of each of the screens used as the metaresonator mirrors contains two lengths of rectangular waveguides of different transverse sections. Design/methodology/approach: An operator method for solving the 3D problems of electromagnetic wave diffraction by multielement two-dimensionally periodic structures is used in the study. The computation algorithm uses the partial domain technique and the method of generalized scattering matrices. Findings: As follows from the results of the numerical modeling made, the magnitude of the plane wave reflected from the metaresonator turns to zero at fixed frequencies lying below the cutoff frequencies for the rectangular waveguide sections embedded in the resonator mirrors. The effect of the total electromagnetic wave transmission through the metaresonator at the first lower frequency is characterized by a strong localization of the electromagnetic field in the resonator volume. The reason is excitation of the metaresonator by the exponentially descending field penetrating inside the resonator through the evanescent holes at the resonance frequency. The second low-frequency resonance of the total electromagnetic wave transmission through the metaresonator is associated with the trapped-mode resonance, which is observed in multielement two-dimensionally periodic structures. This case is characterized by a strong localization of the electromagnetic field from both sides near the metaresonator mirror surfaces. Conclusions: The unique electrodynamic properties of the metaresonator can find application in the devices for measuring the electrophysical parameters of composite materials with high losses. The effect of strong localization of the electromagnetic field both in the resonator volume and near the mirror surfaces can be used for monitoring the gaseous substances in crowded places. Key words: two-dimensionally periodic screen; rectangular waveguide; Fabry-Perot metaresonator; reflection factor; evanescent waveguide; trapped-mode resonance
{"title":"A FABRY-PEROT METARESONATOR SUPPORTING TRAPPED-MODE RESONANCES","authors":"A. Gribovsky","doi":"10.15407/rpra26.04.344","DOIUrl":"https://doi.org/10.15407/rpra26.04.344","url":null,"abstract":"Purpose: Investigation of the electrodynamic properties of a Fabry-Perot metaresonator formed by two parallel perfectly conducting, two-dimensionally periodic, two-element screens of finite thickness with rectangular holes. The resonator is excited by a plane linearly polarized electromagnetic wave. The basic cell of each of the screens used as the metaresonator mirrors contains two lengths of rectangular waveguides of different transverse sections. Design/methodology/approach: An operator method for solving the 3D problems of electromagnetic wave diffraction by multielement two-dimensionally periodic structures is used in the study. The computation algorithm uses the partial domain technique and the method of generalized scattering matrices. Findings: As follows from the results of the numerical modeling made, the magnitude of the plane wave reflected from the metaresonator turns to zero at fixed frequencies lying below the cutoff frequencies for the rectangular waveguide sections embedded in the resonator mirrors. The effect of the total electromagnetic wave transmission through the metaresonator at the first lower frequency is characterized by a strong localization of the electromagnetic field in the resonator volume. The reason is excitation of the metaresonator by the exponentially descending field penetrating inside the resonator through the evanescent holes at the resonance frequency. The second low-frequency resonance of the total electromagnetic wave transmission through the metaresonator is associated with the trapped-mode resonance, which is observed in multielement two-dimensionally periodic structures. This case is characterized by a strong localization of the electromagnetic field from both sides near the metaresonator mirror surfaces. Conclusions: The unique electrodynamic properties of the metaresonator can find application in the devices for measuring the electrophysical parameters of composite materials with high losses. The effect of strong localization of the electromagnetic field both in the resonator volume and near the mirror surfaces can be used for monitoring the gaseous substances in crowded places. Key words: two-dimensionally periodic screen; rectangular waveguide; Fabry-Perot metaresonator; reflection factor; evanescent waveguide; trapped-mode resonance","PeriodicalId":33380,"journal":{"name":"Radio Physics and Radio Astronomy","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49345419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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